In case anyone is interested and has a similar requirement, here's how I
solved this problem (source below):
Usage:
var parser = new QueryParser("fulltext", new StandardAnalyzer());
parser.SetDefaultOperator(QueryParser.Operator.AND);
var searchQuery = parser.Parse("car");
var softBooleanQuery = new SoftBooleanQuery();
var visibleQuery = new SoftTermQuery(new Term("visible", "1"));
softBooleanQuery.Add(searchQuery, BooleanClause.Occur.MUST);
softBooleanQuery.Add(visibleQuery, BooleanClause.Occur.MUST);
... search with softBooleanQuery ...
Helper classes:
public class SoftBooleanQuery : BooleanQuery
{
public override Query Rewrite(IndexReader reader)
{
restart:
foreach (BooleanClause clause in Clauses())
{
var softQuery = clause.GetQuery() as SoftTermQuery;
if (softQuery != null)
{
if (softQuery.Rewrite(reader) == null)
{
// rewritten query is null, remove it from the
clauses (see SoftTermQuery.Rewrite)
Clauses().Remove(clause);
goto restart;
}
}
}
return base.Rewrite(reader);
}
}
public class SoftTermQuery : TermQuery
{
public SoftTermQuery(Term t) : base(t)
{
}
public static bool IsTermIndexed(IndexReader reader, Term t)
{
return reader.Terms(t).Term().Field() == t.Field();
}
public override Query Rewrite(IndexReader reader)
{
Term t = GetTerm();
// if the term does not exist in this IndexReader, return null
return IsTermIndexed(reader, t) ? base.Rewrite(reader) : null;
}
public override string ToString(string field)
{
return base.ToString(field);
}
}
Andrew C. Smith wrote:
Maybe you can perform the OR clause with the MultiSearcher and use a custom
made QueryFilter to filter the results that you don't need out of the first
index.
~Andrew
On Wed, Jul 29, 2009 at 3:22 PM, Andrei Alecu <[email protected]>wrote:
Right, I was doing two separate searches before, but I was hoping there was
a better way.
Thanks.
Digy wrote:
Either you have to reindex "Index A" and add a "visible" field with values
both 0 and 1, or make two seperate searches.
DIGY
-----Original Message-----
From: Andrei Alecu [mailto:[email protected]] Sent: Wednesday, July
29, 2009 9:54 PM
To: [email protected]
Subject: Is this query possible?
Hello all,
I have a MultiSearcher searching two separate indexes.
One of the indexes (index B) has some extra terms in its documents
compared to the other (index A).
Consider this scenario:
Index A documents:
field: fulltext
Index B documents:
field: fulltext
field: visible
I want for a query such as :
fulltext:"car" AND visible:1
To return all the matching "car" results in Index A, thus ignoring the
'visibile' constraint if it's not defined for the document. How can I do
that? Right now the results completely skip Index A because of no matching
'visible' field.
Thanks.
